The present invention relates to a golf ball composed of a core, an intermediate layer and a cover having a plurality of dimples formed thereon. More specifically, the invention relates to a golf ball which, in terms of distance and other properties, is beneficial for competitive use by highly skilled golfers and amateur golfers.
It is known that a golf ball, when hit at a low spin rate and a high launch angle, will travel a longer distance. With recent advances in golfing gear (balls and clubs), it is no longer unusual for a ball to be hit under exceedingly low spin conditions such as a backspin of 2,000 rpm. Under such low spin conditions, the ball has a low coefficient of drag (CD), which works to increase the distance of travel. However, with conventional dimples, in the low-velocity region after the ball has passed through the highest point of its trajectory, a loss of distance occurs due to insufficient lift and the resulting drop in trajectory.
Recently, golf balls often have an internal construction with a plurality of layers. The layers enclosing the core of a ball typically include a cover and an intermediate layer situated between the core and the cover. Numerous disclosures have been made in the art relating to the use of materials for forming such an intermediate layer which are based on highly neutralized polymers (see the ten patent documents listed below).
JP-A 2006-087949
JP-A 2006-087948
JP-A 2005-342532
JP-A 2005-218859
JP-A 2005-218858
JP-A 2003-175129
JP-A 2002-345999
JP-A 2002-315848
JP-A 2002-085589
JP-A 2001-218873
However, in these golf balls, the rebound sometimes decreases on account of the cover material which encloses the intermediate layer. Hence, there remains room for further improvement in the distance traveled by the ball.
In addition, the patent documents listed below relate to golf balls in which a sphere composed of a core encased by an intermediate layer has an improved deflection or initial velocity, although there remains room for improvement in the distance traveled by such balls.
JP-A 2006-230661
JP-A 2005-211656